/*
By starting at the top of the triangle below and moving to adjacent numbers on the row below, the maximum total from top to bottom is 23.
37 4
2 4 6
8 5 9 3
That is, 3 + 7 + 4 + 9 = 23.
Find the maximum total from top to bottom of the triangle below:
75
95 64
17 47 82
18 35 87 10
20 04 82 47 65
19 01 23 75 03 34
88 02 77 73 07 63 67
99 65 04 28 06 16 70 92
41 41 26 56 83 40 80 70 33
41 48 72 33 47 32 37 16 94 29
53 71 44 65 25 43 91 52 97 51 14
70 11 33 28 77 73 17 78 39 68 17 57
91 71 52 38 17 14 91 43 58 50 27 29 48
63 66 04 68 89 53 67 30 73 16 69 87 40 31
04 62 98 27 23 09 70 98 73 93 38 53 60 04 23
NOTE: As there are only 16384 routes, it is possible to solve this problem by trying every route. However, Problem 67, is the same challenge with a triangle containing one-hundred rows; it cannot be solved by brute force, and requires a clever method! ;o)

Anser:1074
Time:311.77µs
*/
package main

import (
	"fmt"
	"strconv"
	"strings"
	"time"
)

const str = `75
95 64
17 47 82
18 35 87 10
20 04 82 47 65
19 01 23 75 03 34
88 02 77 73 07 63 67
99 65 04 28 06 16 70 92
41 41 26 56 83 40 80 70 33
41 48 72 33 47 32 37 16 94 29
53 71 44 65 25 43 91 52 97 51 14
70 11 33 28 77 73 17 78 39 68 17 57
91 71 52 38 17 14 91 43 58 50 27 29 48
63 66 04 68 89 53 67 30 73 16 69 87 40 31
04 62 98 27 23 09 70 98 73 93 38 53 60 04 23`

func main() {
	tstart := time.Now()
	strs := strings.Split(str, "\n")
	tri := make([][]int, len(strs))
	for i := 0; i < len(strs); i++ {
		numbers := strings.Split(strs[i], " ")
		tri[i] = make([]int, len(numbers))
		for j := 0; j < len(numbers); j++ {
			tri[i][j], _ = strconv.Atoi(numbers[j])
		}
	}
	fmt.Println(sumPath(0, 0, tri))
	tend := time.Now()
	fmt.Println(tend.Sub(tstart))
}

func sumPath(row, col int, tri [][]int) int {
	if row >= len(tri) {
		return 0
	}
	return tri[row][col] + max(sumPath(row+1, col, tri), sumPath(row+1, col+1, tri))
}
func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}
